Swimming is beneficial exercise, especially in physical therapy. Often some type of flotation support and/or restraint is desirable either to allow normal swimming exercise in a confined body of water, such as a hot tub or a small part of a large pool, or because a swimmer undergoing physical therapy is injured in such a manner that flotation and restraint are necessary for the exercise to be conducted safely.
In the past, therefore, a number of restraint and flotation systems have been developed to permit "swimming in place".
The prior art in this field can be divided into two general types of apparatus. The first are passive restraints such as is illustrated by U.S. Pat. No. 4,109,905, wherein a simple lasso goes around the abdomen of a swimmer to provide a tether that prevents the swimmer from moving as he exercises. U.S. Pat. No. 3,988,020 also shows a passive restraint wherein a pair of flexible lines are attached to a belt on the swimmer and anchored to the side of the pool. Such devices do not provide flotation and thus accomplish only the function of allowing a swimmer to "swim in place".
The second general class of prior art in this area can be categorized as "swimming supports". These devices support a swimmer in the water and are often used for exercise in physical therapy. A good example of this type of prior art is found in U.S. Pat. No. 3,112,928, which teaches a fixed support that sits in a swimming pool or is imbedded in concrete. This support has a telescoping mast that terminates in a small platform. The swimmer balances on the platform and exercises by making swimming movements with his arms and legs. This type of device has a number of major defects. Chief among these is the fact that the swimmer must be sufficiently coordinated to balance on top of a flat slab or platform. The support is only useful so long as the swimmer does not roll off the support. This inhibits the three-dimensional body motion that accompanies normal swimming.
Another support of this type is illustrated in German Pat. No. 2,623,091, which provides for an annular belt that fits around the waist of a swimmer and is tied to two sides of a swimming pool. This device supports the swimmer in the water by tension on the restraining lines that anchor him to the side of the pool. These lines, since they are under tension, prevent the yaw motion that is normal in swimming.
Still another support of this type is suggested by U.S. Pat. No. 1,069,691, which is a life preserver with a neck support. In use, this device fails to adequately simulate the normal swimming movement by restraining head and neck movements and by emphasizing vertical, rather than longitudinal buoyancy.
Swimming is naturally a three-dimensional activity. A swimmer moves about three axes, i.e., roll, pitch and yaw, simultaneously in the act of properly exercising a swimming stroke. Normally a swimmer is supported by the buoyancy of water and the roll, pitch and yaw of swimming motions occur naturally. One defect common to all prior art discovered by the present inventor is that all prior art devices either do not provide flotation support or they restrain the swimmer using them from naturally exercising by preventing motion about at least one axis during the exercise. For example, U.S. Pat. No. 3,112,928, prevents motion about the pitch axis while the German Patent referred to above prevents a swimmer from rotating on the yaw axis.
It is an object of the present invention to provide a combination flotation and restraint device that allows a swimmer to engage in simultaneous rotation about all three axes, i.e., roll, pitch and yaw, whereby a swimmer may accomplish a natural swimming stroke while being supported by a flotation device passively restrained from the forward motion that would normally accompany such a stroke.
Another object of the present invention is to provide a means of accomplishing natural physical therapy in a limited space.
Still a further object of the present invention is to provide a flotation and restraint device for natural physical therapy by swimming that is simple, relatively foolproof and cheap to manufacture.
Yet still a further purpose of the present invention is to provide a restraining device whereby the swimmer is anchored to the bottom of a pool of water such that a large number of swimmers may exercise in a relatively small pool.